IPhone 5 journal: Finding the best, cheapest carrier

You may think you're buying an iPhone from Apple for $199 and up, but in most cases you're really signing up for 24 months of payments to one wireless carrier or another. Choose wisely.

If what you care about most is widespread coverage, it's easy: As CNNMoney's graphic shows, Verizon's 4G LTE coverage overwhelms AT&T's, which in turn dwarfs Sprint's. But if your region has or will soon have LTE from all three -- or if you're fine with 3G -- your choice remains wide open.

Choosing on cost isn't so simple. Sprint has the cheapest plan for a data-hungry user: $80 for unlimited data and texting, plus 450 peak minutes. If you're positive you won't use much data and won't text at all, however, you can pay $60 a month at AT&T for a Nation plan with only 300 MB of data and zero text messages included.

In some parts of the U.S., you can now buy an iPhone 5 from the prepaid carrier Cricket Wireless. It charges $500 and up for the phone itself but asks just $55 a month, no contract required, for unlimited calling and texting plus 2.5 GB of full-speed data. Other regional carriers are also now selling the iPhone 5 bundled with service plans, sometimes at smaller discounts.

An iPhone 5 does include one longer-term advantage, though: Apple's history strongly suggests you'll get operating-system updates for the next few years. The neglectful habits of Android vendors, who typically take many months to push out updates or skip them entirely, offer no such reassurance.